Absorption refrigerator



March 9,1943: .1. Lun-:Gow Erm. 2,313,707

I ABsoRPTIoN REFRIGERATOR' Filed mig. '15, 19:59v 7 sheets-Sheet 2 March 9, 1943- Y J. LrrHGow Erm. l j ,2,313,707

ABsoRPTIoN REFRIGERATOR l Filed Aug. 15, 1939 'v sheets-sheet s l March 9, 1943. J.. LlTHCiw ErL 3139707 ABsoRPTroN nERaERAToR v Filed Aug. 15, 1959' 'r sheets-:snaai 4 f March 9,1943. J. I ITI-lcaowA Erm.r 2,313,707

` ABSQRPTION REFRIGERATOR Filed A u'g. 15, 1939 7 Sheets-Sheet- 6 I lqow. Jac son.

Mal-d1 9, 1943. J. www En.. 2,313,707

ABSORPTION 'REFRIGERATCQR4 Filed Aug.` 15. 19:59 #sheets-sheet '7 ..-pms Mag, 1943 naar ssonrrron nnrmcnns'ron Johnl Lithgow and Leslie Ohio, cago, Ill..

K. Jackson, Cleveland, asslgnors to Sears,

a corporation o! New York Roebuck and Co., Chi- Application August 15, 1939, Serial No. 290,314

(Cl. ca -11s).

22 Claims.

Ou'r invention relates to refrigerating apparatusand especially to household refrigerators of the intermittent air-cooled absorption type.

still and condenser.

The location of the still and condenser in a single iiue gave rise to another disadvantage. In

' many instances, it is advisable or required because of iire regulations to attach an outlet or 55 stove pipe to the unit to carry oi products of combustion., 'Ihe ordinary outlet to a ue which houses both the condenser and burner was too More particularly, our invention relates to an inlarge to att-ach an ordinary stove pipe. When termittent absorption system of the type involv- 5 the ordinary flue outlet is constricted for this ing a dead end condenser, which type is known purpose, the draft through the condenser is likeas the 1--3-2 system, where 1 designates the ly to be interfered with. Where a kerosene burngenerator-absorber, 2 the condenser, and 3 the er is used, it is often especially desirable 'to lead evaporator. In this type of system the flow of reoff the products of combustion and fumes therefrigerant during the .generating cycle from the l `from and this also was rendered rather diillcult generatorv passes through at least a portion of the by prior constructions. These disadvantages evaporator on the wayto the condenser where it were particularly noticeable in the air cooled inis collected. termittent absorption type of refrigerator vbe Refrigerators of this particular type have been cause of the relatively large burner in this type of subject to many disadvantages. As a rule, they unit as compared to the continuous type. were extremely bulky as compared to the o rdi- It is an object of our invention, therefore, to nary mechanical refrigerator. This was due provide in an apparatus of the type referred to, largelytothe necessary complicated arrangement a novel arrangement of nues whereby the hot of iiues.- condensers and the like within the reL v products of combustion from the burner and hot friger-ation cabinet. Another disadvantage of the air passing from around the still will be com- I intermittent system was the lack of eilicient depletely separated from the main flue housing the hydration which resulted in a large quantity of condenser, the dehydrator and the absorber coolabsorbent being carried over into the evaporator ing coil of the unit. 7 of the system during the generating cycle. Drains A; second object of our invention is the provihave been provided to get .rid of the accumulated sion' of a separate generator housing and a relaexcess of absorbent so carried over... but these ltively small flue leading therefrom, the flue being drains either did not' drain enough of the abespecially adapted to connection to an ordinary sorbent or drained so eillciently and thoroughly stovel pipe. that refrigerantwas lcarried back to the genera- -Another object of our inventionl is the provitoior still-absorber of the system, with a resuit- 30 sion of a novel supporting means for the burner ing lack of economy. Another disadvatange of l control and fuel tank of an intermittent'absorpthe prior systems of this type was the delay in tion refrigeration system which will enable the the starting of the refrigeration cycle caused by various units to be easily removed for adjustment an insuilicient amount of refrigerant in the evapand replacement.

orator at the beginning of the cycle'. Still another 35 .A further object of our invention is the providisadvantage of the intermittent absorption resion of a novel burner for an intermittent ab-v frigerators of the prior art, and particularly sorption refrigerator especially adapted yfor easy those of the air-cooled variety, was the use of a removal from the unit.

common ue incorporating the still andthe con- Still another object of our invention is the prodenser of the system. -Prior workers in the art 4'0 vision of a novel burner especially free from believed that the incorporation of the still and leakage. the condenser in a single flue was necessary in Still another object-is to provide a refrigerator order to promote the flow of air through the conmechanism having anovel arrangement of condenser. On the contrary, we havel discovered denser and absorber cooling coil whereby the heat that the incorporation of the still in the same flue given' off by the absorber cooling coil during the with the condenser meant subjecting the stlllabsorption period may be utilized to improve the burner tola large uneven volume of air. We disefciency of operation of the mechanism. covered that this resulted in uneven burning and Another object is to provide a refrigerator operation of the still and that it was necessary y mechanism wherein the condenser coil and the for eilicient operation to completely separate the absorber coil are positioned in heat exchange relationship so that an increase of ,pressure will be effected in the' condenser early in the refrigerating cycle which is effective to force refrigerant from the condenser to the evaporator. A further object of our inventionis to provide a mechanism of the type referred to which will occupy a minimum of space so as to leave a maximum amount of space for the refrigerating chamber. l v

Another object is to provide a dehydrator especially adapted to t in a relatively narrow flue at the rear of the cabinet while at the same time providing a maximum heat exchange area.

A further object of our invention is to provide a drain conduit for absorbent liquor leading from the evaporator which will be effectiveto return such `liquor to the still-absorber at the beginning of the generating period. v

Another object is to provide a drainage system which will drain for a limited period and be substantially incapable of draining more than a limited quantity of weak liquor from the evaporator of the refrigeration system.

Still another object is to provide a novel arrangementof dehydrator conduits and fins attached thereto which may be easily assembled` within a refrigerator cabinet.v

Various other objects vand advantages will become apparent from the subsequent description and drawings.

Referring to the drawings forming part of this specification and illustrating a preferred embodiment of our invention:

Fig. 1 is a vertical section of a refrigerator taken on the line l-I of Fig. 2.

Fig. 2 is a sectional view taken substantiauy along the line 2,-2 of Fig. 1.

Fig. 3 is a sectional view taken substantially along the line 3--3 of Fig. 1.

Fig. 4 is a diagrammatic illustration of one form of the apparatus embodying our invention.

Fig. 5 is a-diagrammatic illustration of a modiiication of our invention.

Fig. 6 is a diagrammaticillustration of a third modification.

Fig. 7 is a diagrammatic illustration of a fourth modication.

Fig. 8 is a detail section taken on the line 8-8 of Fig. 11.

Fig. 9 is a side elevation of a iin embodyingourl invention, y

Fig. 10 is an enlarged detail of a tab attaching means for a iin.

Fig. 11 is an elevation of one form of our dehydrator.

Fig. 12- is an elevation of a second form of dehydrator. C

Fig. 13 is a section taken substantially along the line I3-I3 of Fig. 12.

Fig. 14 is a. detail section of a iin structure taken along the line I 4-I4 of Fig. 12. f

`Fig. 15 is an elevation of a third type of de-l hydrator according to our invention,

' mainder of the apparatus as by a side wall I1av Fig. 16 is a front elevation of the lower portion of a refrigerator showing the arrangement of the burner, fuel tank and control.

Fig. 17 is a diagrammatic plan view of the lower portion of a. refrigerator partly broken away. Fig. 18 is a vertical section of the burner. Fig. 19 is a section of the burner taken on -the line I9-I9 of Fig. 18. Referring to Figs. 1 to 3, the numeral III indicates a. cabinet of 4any type suitable foi housing the refrigerating mechanism of our invention and for providing a refrigeration space. A chamber I I, which may serve as a refrigeration space and also houses an evaporator I2, is bounded by a back wall I3 and a bottom wall I4 and suitable side walls I5 and I8. It will be understood that the walls of the refrigeration space are properly insulated in accordance with the accepted practice. However, for the convenience of illustration, the cabinet structure is indicated more or 'apparatus and to form a flue, as-will hereinafter be described.

Below the refrigeration space II is a space I1 in which is disposed a still-absorber or generator absorber I8 heated bya burner I9 of any suitable type when distillation of refrigerant is desired. The space I1 is completely isolated from the reand by a bame or wall 20 disposed above and in front of thestill-absorber I8 and -extending downwardly in front of the still-absorber to the bottom of the cabinet, it being understood that a suitable door is provided to allow access to the still-absorber and the burner forwthe.piirpose of adjustment, etc. The rear vof the space 'I1 is closed by wall or baille 2I which extends upwardly in spaced relation to the baille 20, while another baille 2|' has a vertical portion parallel to baille 2I and spaced therefrom to provide an insulating air space, this vertical portion starting above the bottom. of the casing and then sloping upwardly and rearwardly, as seen clearly in Figs. 2 and 3. to form a rearwardly extending flue 22 communieating with flue I1. As will be seen from the drawings the baffles 20 and 2| conform at least ind part to the shape of the still I8 so as to direct hot gases from the burner around the still to increase eifciency. The ilue 22 communicates with a. vertical pipe or flue 23 which serves to carry off to the atmosphere the products of combustion and excess heat from the burner I3. Surrounding the pipe or flue 23 and occupying the rest of the space between the wally I3 andthe rear of the cabinet is a main iiue 24 which, of course, like the flue 23, is Well insulated from the refrigeration space II. A relatively large inletf25 is provided for the iiue 24 at the bottoin of the cabinet and a relatively large outlet 26 is provided for the iiue 24 at the top of the cabinet.

burner operation. The iiue 23 terminates at the top of the cabinet in a relatively small opening 28 which preferably may be directly connected to any suitable outlet pipe or stove pipe if desired.

From the still I8 extends a conduit or steam tube 29 having an up les and a down leg, the latter discharging into the lower portion of a trap 30. A vapor discharge outlet -.3I rises from the upper portion of the trap 30 and is connected to asuitable dehydrator 32 of -a type to be hereinafter described in detail. The lower portions of the dehydrator are connected to the trap 3D by a. conduit 33 in order to permit the return thereto of water separatedfrom the vapor, and the trap in turn communicates through a. conduit 34 with the still-absorber, the conduit 34 serving to maintain a constant level of liquid in the trap.

'I'he outlet end of the dehydratorcommunicates by means of a conduit 35 with the evaporator take-off M. From the take-oil 44 a conduit 36 communicates with the lower portieril of a chamber 31, the latter being disposed in a space 38 bounded by the baille 2| on the front and on the rear by the rear wall of the cabinet l' and extending from side to side thereof. From A drain for absorbent from the evaporator is. f

also provided, as is customary in an intermittent 4 absorption system. Referring to Fig. 1 the drain comprises a tube 45 which extends upwardly from a well or sump in the evaporator coils I2a and communicates with anenlarged vessel 46, the latter discharging at the bottom thereof into a conduit 41 communicating with vthe trap 30.

` Another tube 48 extends upwardly from the evaporator receiver I2b and communicates with a chamber or enlargement 49. 'I'he chamber 49 is connectedto the top of the enlarged vessel 46 by conduit 49a. The drain just described will be further described in detail as to function and operation in connection with the modification of the device disclosed in Fig. 4.

A gas return conduit 50 leads from the evapo-v rator to the up leg 5I of an absorber'cooling coil 52. dissipate the heat in the still-absorber. Preferably, it takes the form of a relatively flat horizontally disposed coil or series of coils located ljust below and in heat exchange with the condenser coil 4Il. As dlagrammatically shown', the absorber coil 52 consists of a heat dissipating coil portion providedr with fins, an up leg 6I and This coil may be of any suitable design to a down leg 53 communicating with the still I3,

positioned in the space 38 between the condenser cooling coil and the condenser receiver 4 2. The advantages of this arrangement will be hereinafter discussed. I

During the heating or generating period, the burner I9 will function to heat the still I3, and the products of combustion will be discharged up the flue 23 and the outlet 28. Air for combustion will be drawn into the space at 21. Refrigerant gas, preferably ammonia, and some absorbent, preferably water, is distilled off in the still I8,4 passing up the steam tube 29 to the trap 30. A portion of the water vapor will separate out4 during the passage up the steam tube and will return to the still through the trap overflow 34. The remaining vapors of water and ammonia will pass into the dehydrator through con- 4 duit 3| where substantially all of the water will be separated and returned to the trap through conduit 33. The dehydrated ammonia, will flow toward the evaporator through conduit 35. Since the evaporator receiver I2b is usually insulated, very little condensation of the ammonia will take place therein at this period, and substantially all of the ammonia, in gaseous'form will pass through the conduit 36 to the chamber 31. From the chamber 31 theammonia gas'will flow through 39 to the condenser coil 40 and be condensed` therein. 'I'hecondensed ammonia I will flow through conduit 4I and be collected in condenser receiver 42. Y

At the beginning of the refrigerating period, the burner I9 will be turned of! either manually or by means of a suitable controlling mechanism.,

The still 'I8 will then function as an absorber.

The shut-oiof the burner `I8`will reduce the pressure on the still 'side of the system, and the pressure of liquid ammonia under ordinary temperature conditions will serve to/force the liquelied ammonia in condenser receiver 42 back up the conduit 36 to the evaporator. facilitated by the particular arrangement of the absorber cooling coil and condenser coil, in-the following manner: Almost immediately at the beginningof this cycle,the reduction of pressure in the generator will draw gas from the evaporator, the gas returning to the still-absorber throughy conduit 50. This return of the gas will create a flow of liquid up absorber cooling coil leg 5I, and, as a result, liquid will be drawn from the still. down leg 53 and through the absorber cooling coil 5.2i This passage of hot liquid from the still through the absorber cooling coil will transmit some heat to the condenser coil 4,0 because of the heat exchange relationship between the condenser coil and the absorber coil. The

heating of the condenser coil 40 will increase the pressure in the condenser coil. 4This increase turn of the refrigerant to the evaporator lengthened the refrigerating C cycle approximately twenty per cent. y

,It is to be noted that heat is transmitted from the absorbercooling coil to the condenser coil.

only during the refrigerating or absorption period, since' the absorber cooling coil is so con-'- structed that no current of fluid from the stillabsorber is created except during the absorption period. vThis flow of uid through the absorber' cooling coil is -instituted, as hereinbefiore explained, by the'flow of gas from the evaporator into the up leg 5I of the absorber cooling coil.`

It is to be noted particularly that in the ap- -paratus just described the flue 24 is completelyr out of communication with the flue 23. v.During thevgenerating period, the draft of cooling air through the condenser is entirely` generated by the flue action of the hot condenser coils and the dehydrator, and especially the latter. As can be seen particularly in Fig. 3, the dehydrator sub-- .stantially fills the upper portion of the relative- *,ly narrow ue 24. Several advantages result from the disposal of the dehydrator in the relatively narrow flue above the condenser. 'I'his positioning of the dehydrator to receivev the air warmed by passage through the condenser prevents undue condensation of ammonia, in the de- -hydrator.

through the condenser, has been heated to ap- In other words, the air, after passing increased quantity of ammonia.

Even though the greater part of the absorbent s or water volatilized from the still is taken out by the dehydrator, as hereinbefore set forth, a certain amount ofl absorbent fluid Vor water passes .over to the evaporator I2, and it is essential for theeicient prolonged operation of. the machine that this water be periodically returned tothe This action is still. For this reason there is provided an absorbent return or drain.- This absorbent return or drain, as. shown in Fig. 1, comprises a conduit 45 having its lower end in a sump or low point in the evaporator coils I2a and a relief conduit 48 connecting with an enlarged portion 49, which has its lower end disposed in the lower portion of the evaporator receiver 12b. Both of these conduits communicate with the enlarged chamber 46, and the enlarged chamber, in turn, communicates with and is liquid-sealed in a conduit communicating with the trap 30. This type of drain is disclosed in detail in Fig. 4, where the still-absorber is represented by reference numeral I8 and the evaporator by reference numeral I2. The condenser and dehydrator are shown in this figure in a diagrammatic fashion and operate in a manner similar to the description as hereinbefore'set forth.

The drain according to our invention Aoperates in the following manner: During the initial portion of the generating cycle, the pressure in the system will berelatively high. At this time there will be sufficient iluid in the evaporator receiver I2b to seal the lower end of the conduit 4B. The resultant pressure in the system will therefore tend to force fluid up the conduit 45. This fluid will spill over into the enlarged chamber 46 and will accumulate in the lower part of the enlarged chamber and in the conduit 41 leading therefrom. Itl will beenoted that the conduit 41 terminates at its lower end in the conduit 33 which leads from the dehydrator. The flow of liquid returning from the dehydrator will assist the flow of liquid from the conduit 41. Any liquid present inthe evaporator l2 and in the evaporator storabe I2B` will therefore tend to drain through the conduit 45 until the end of the conduit 48 has been uncovered. As soon as the end of the conduit 48 has been uncovered, no further drainage can take place since the conduit 48 will transmit pressure to the enlarged chamber 45. The con'- duit 45 will, therefore, be in a pressure balance at both of.its ends. No liquid can be forced up the conduit 45, and the liquid inthe lower conduit 41 standing above trap level willl drain into the trap,

During the generating cycle, it is understood that substantially no `refrigerant will be condensed in the evaporator storage 12B since this storage is preferably insulated, and therefore, further drains will be minimized. This particuqv lar form of drain is advantageous since it :nain-` tains a constant supply of fluid in the evaporator coils I2a. The maintenance of a constant supp-V ply of fluid in the evaporator coils prevents the the upper end of the conduit 33 is positioned above the normal liquid level L in the trap .8l and, therefore, some liquid from the dehydrator will be trapped in the conduit 33 at all times. The liquid sealing of the end of the drain will serve to balance the pressures in the drainV sys- .passage of ammonia through the evaporator coils y.

during the generating period and therefore prevents any warming action on the refrigeration space at this time bythe condensation of ammo nia. It will be noted particularly that the upper portion of conduit 48 is located at a higher level than conduit .45. This positioning of the conduit 48 and the enlargedsection 49 prevents drainage through the conduit 48.v Since the water or absorbent in the evaporator is heavier than the am monia, this arrangement insures drainage from the lowermost portion of the evaporator coils and therefore absorbent rather than refrigerant is returned to the still through the`drainage system. It is essential that the lower end of the drain -41 be liquid-sealed during the evaporation period since this prevents drainage at this time. It will be noted that this effect is secured because tern during the refrigeration period, and, therefore, no drainage can occur at this time.

Another type of drain in accordance with our invention is disclosed in Fig. 5. In thismodiflca.- tion an auxiliary trap chamber 30a is provided, and the lower end of the drain 41 communicates with the auxiliary trap chamber below the liquid level L therein. This type of drain is also pro' vided with an enlarged section 46 and a section 4I communicating with the lower portion of the evaporator. A pressure relief conduit is also provided in this type of drain, but in this instance the pressure relief conduit, instead of communicatingwith the evaporator receiver i2b, communicates with the upper portion of the auxiliary trap chamber 30a. This relief conduit is indicated as 54 in the drawing. It will be noted particularly that the auxiliary trap cham-ber 30a surrounds and is, therefore, in heat exchange with the steam tube 29 which leads from the still I8 to the trap ASli. the evaporator also occurs in this modification at the beginning of the generating period. At the beginning of this period, water or weak liquor from the bottom of the evaporator coilsis forced up the conduit 45 and spills over into the enlarged section 46, from there returning through conduit 41 to the auxiliary trap chamber 30a and through a conduit to the trap 30. From the trap 30 the weak liquid will overflow through the trap overflow conduit 34 to the still. n

After the weak liquor has been drained froml the evaporator tubes, a certain amount of condensation of ammonia will take place therein, and it is necessary to provide some means to prevent further drainage. This is provided by the arrangement shown in Fig. 5 inthe following manner. It will be noted thatl the conduit 33 leading from the dehydrator enters the auxiliary trap chamber 36a. During the generating period, therefore, the water separated in the dehydrator will enter auxiliary trap chamber 30a before entering the trap 30 and overowing to the still I8. This dehydrator liquid is comparatively rich in ammonia since a lcertain amount of ammonia is condensed in the dehydrator along with the separated water at normal dehydrator temperatures. Since the auxiliary trap chamber 30a is in heat exchange with the hot steam tube, the ammonia in the dehydrator liquid will be volatillzed and the 'vapor driven up relief conduit 54 to the enlargedv early part of the generating cycle in a-manner 'similar to that described in connection with Fig. 5,

the weak liquor from the evaporator passing up conduit 45 through the enlarged chamber 4l and down vconduit 41. The conduit 41 in this modification communicates with the upper portion of the 'auxiliary chamber or` dome 30h. When the Drainage of absorbent or water fromv terminates the drain by balancing thepressure liquid is drained into the dome, a portion of it is flashed into gas bythe heat of the trap 30, and the volatilized gas returns to the enlarged chamber 46 through the relief conduit 54. This return of gas equalizes the pressure in a manner similar to that described in connection with Fig. and prevents further drainage of refrigerant through the drain conduit 45. Liquid from the@ dehydrator returning through conduit 33 to the dome or auxiliary trap chamber 30h furnishes an additional supply of ammonia to be flashed into gas during the generating period. The ammonia thus continuously volatilized in the chamber 30h creates a back pressure through conduit 54, in the enlarged chamber 46 and prevents any further drain through the conduit 46, this manner of operation being similar to the operation of the modification' disclosed in Fig. 5.

It. will be noted that in each of the modifications of the device described in Figs. 4, 5, and 6, thel dehydrator is provided with a spillpot or gas and liquid separating chamber 55. The function of this gas and liquid separating chamber will be specifically described in connection with the modification of the dehydrator shown particularly in Figs. 12 and 15. The use of a chamber of this type is not essential in the dehydrator structure, and a dehydrator will -be hereinafter described which communicates directly with the trap 30.4 It is to be understood that where a drain of the type disclosed and discussed-in connection with Figs. 4, 5, and 6 is used, the gas and liquid separating chamber is not essential.

, In the modification ofthe drain shown in Fig. '7, there is incorporated the advantages of both the drain of Fig. 4 and the drain of Fig. 5. It is to be noted that the drain 'of Fig. 4 willmaintain a certain amount of refrigerant in the evaporator coils inasmuchv as the pressure relief conduit 48 will be effective to positively stop thedrain as at both ends of the conduit 45. The liquid in the `enlarged chamber 46 and the conduit 41 then runs into the trap through the conduit 33 and the auxiliary trap chamber 30a. Due to the heat exchange between the chamber 30a,- and the steam tube 23. a portion of the liquid fed through conduit 33 from the dehydrator will be continuously volatilized during the generating period Whether or not the conduit 48 is liquid-sealed and fed to the top oi the enlarged chamber 46 lthrough conduit 54. The increase of pressure in` the chamber 46 thus caused will prevent any further drainage through the conduit 45 or 48 in the evaporator.

Referring particularly to Fig. 11, there is dis` closed a dehydrator communicating with a trap 30 which is connected to the system as hereinbefore described. The steam tube 29 leading from the still enters the trap 30 adjacent the' bottom thereof. An overflow conduit; 34 is also provided leading from an intermediate section of the trap 30 and serving to return weak liquor" in a relatively narrow and wide flue at the rear of a. refrigerator cabinet, as shown in Figs. 1 to 3. It is to be understood that instead of a single tube a plurality of welded together sections may be employed and that each reach may be cons'oon as the end thereof is uncovered. In this modification, however, 'if additional refrigerant is condensed inthe storage I2b, a further drain can take place during the generating' period. This is not trueof the modification of Fig. 5, inasmuch as the pressure relief conduit 54 will be effective to balance the pressure in the enlarged chamber 46 by supplying refrigerant thereto during the gener'ating period. This will effective ly prevent any further drainage at this time. It is to be noted that -both of the modifications shown in Figs. 4 and 5 are incapable of draining during the refrigerating period because their` lower ends are liquid-sealed. 1 Referring to Fig. 7, it will benoted that an auxiliary chamber 36a is also provided in this function to the pressure relief pipe 48 of Fig. 4.

sidered a separate interconnected tube.

The vertical portions of conduit 12 are provided with fins shown in detail inFigs. 8, 9, and 10 to be yhereinafter described. Each of the lower bends of the conduit. 12 is provided with liquid outlets which are designated by the reference nu= merals 15, ,16,- and 11,-respectively. The last vertical conduit 14 communicates with the condenser and evaporator of the refrigeration system, as shown in the other :figures of the application.

The conduit 18v connects the outlets15, 16 and 11 with the trap so that the separated absorbent may be returned thereto. In=order to bring out the positioning of the dehydrator in the system, the lower portion of conduit 13 has also been designated by the reference numeral 3l, the upper portion of conduit 14by the reference numeral I36 and the portion of conduit 18 close to .the trap by the reference numeral 33.

The operation of the dehydrator shown in Fig. l

' 11 is as follows: A mixture of low boiling refrig- 'Ihe lower portion of the drain 41 communicates er portion of the evaporator up the conduit 45 and spills over into the enlarged section 46 until the lower end of the conduit 48 is uncovered. Uncovering of ,the lower ehd of the conduit 48 verant andA absorbent will enter the dehydrator through the conduit 13 and will -pass through the successive vertical reaches ofthe dehydrator.

Where substantially all of the high boiling absorbent will be condensed and returned to the trap through the conduit 13 and the conduits 15, 16, and 11. The refrigerant substantially free from absorbent will flow to the evaporator and condenser of the unit through the conduit 36. It is to be noted that the usual refrigerant is ammonia and the usual absorbent, water and therefore the apparatus here disclosed is termed a dehydrator, although it is obvious that it can be useLi//ffJ `will lie in a different plane.

to separate any high boiling absorbent from a relatively low boiling refrigerant.

The dehydrator disclosed in Fig. 12 is also preferably formed from a single tube. This form of dehydrator, however, although bent in a serpentine formation, has its straight sections lying slightly inclined to the horizontal instead of vertical, as. in the modification Just described. The modification shown in Fig. 12 has but a single outlet for liquid and is further provided with a gas and liquid separating chamber 18. The couduit 3| leading fromthe trap 88 communicates with this type of dehydrator at 88. The dehydrator conduit proper is sloped in a downward direction from 88 and is indicated by reference numeral 8|. The downwardly sloped portion 8| communicates by means of a U-bend 82 with another downwardly sloped portion 88 which, in turn, communicates bymeans of a U- bend 84 with a third downwardly sloped portion 85, the third downwardly sloped portion 85 communicating through a U-bend 88 with the vdownwardly sloped portion 81 which, in turn,

enters the gas and liquid separating chamber 18 adjacent to its top. Each of the successively sloping portions 8|, 88, 85 and 81 slopes downwardly in an opposite direction so that the dehydratorv in general is of zig-zag formation. The gas and liquid separating chamber communicates lat itsupper portion with the conduit 88, leading to the evaporator and at its lower portion with the conduit 88 leading to the trap 38. Both oi these conduits function as set forth in connection with the general description of the device. Each of the sloping relatively straight with a plurality of flns to be hereinafter described which are particularly designed to function in an efficient manner with this type of relatively horizontal tube structure. As shown in Fig. 13, each successive straight portion of this dehydrator is staggered from the next portion so that the group of ns `iust above one another 'I'his staggering of the straight portions of the dehydrator is not essential, as all of the straight portions may lie in the same plane and the dehydrator in .generalv will thus occupy a narrower flue.

Still another form of dehydrator according to our invention is disclosed in Fig. 15. This form is also provided with a gas and liquid separating chamber 88 which functions to separate the de- `hydrated gas from the separated absorbent in a f manner similar to the gas and liquid separating chamber 19 of Fig. 13. The dehydrator proper is composed of a vertically disposed spiral coil 88 communicating at its upper `end with the conduit J 8| leading from the trap 88 and at its lower end y with the gas and liquid separating chamber 88.

and the separated liquid is removedfrom the de" hydrator at a low point. All of them, therefore,

are especiallyl emcient since the' liquid removed i from the gas flowing in a downward direction wetsthe inside of the tubes.

The iin structure which is especially applicable to the form of dehydrator shown in Fig. 11 is shown in detail in Figs. 8, 9 and 10. As shown in these figures, the iin assembly comprises a pair of rfi relatively flat plates 88 and 8|, each plate being positioned on one side of a vertical tube. As shown 'in Fig. 8, each plate is provided with a relatively flat heat exchange portion 82 and an arcuate portion 88 adapted to conform to the dehydrator tube. 'I'hese fiat portions are adapted to be attached to the tubes so that they lie in a vertical plane and 'therefore present a large heat exchange surface to the vertical current of air passing through the ilue 24 of Figs. 1 to 3. Each plate is provided with a tab 84 bent out of the plane of the plate and passing through a cooperating notch or slot 88 in an opposed plate. lThe end of the tab 84 is provided with a reduced section 88 4which forms spacing shoulders 81. The reduced section 88 is twisted during assembly in order to lock the plates 88 and 8| together and to attach the same'to a dehydrator conduit. The plate 88 is also provided with a tab 88 having an entirely. similar function and provided with shoulders and a twisted reduced end portion. As may be seen in Fig. 9, the tabs are stamped out of the body of the plate proper. v Although this type of fastening is preferred, it is obvious that the 0pposed parallel plates may be attached to a dehydrator conduit by means of bolts .or other conventional means such as welding. v The fin structure here disclosed is also adaptable to other heat exchange devices such as condensers and the like.

As shown in Fig. 8, two of these fin assemblies at an angle to each other are preferably mounted on a single vertical dehydrator tube although it is within the scope of our invention to utilize any number of fin assemblies at any suitable angle on a 'single de hydrator tube or heat exchange element. e. *l

The type of fin structure just described is not as eflicient when applied to the dehydrator shown in Fig. 12 as it iswhen applied to dehydrator of Fig. 11. A form of 1in especially adapted for application to the dehydratorof Fig. 12 is shown in detail in Fig. 14. In this form of iin assembly, opposed plates 88 and |88 are provided, each fitting on opposite sides of the dehydrator tube 8|. Each plate 88 and |88 is provided with two relatively fiat portions connected by an arcuate portion adapted to nt the tube 48|. Each fiat portion is providedwith openings Ill located just above the tube 8| and openings |82 located :lust below the tube 8|.

'serving as an outlet for the space below the conduit 8|. It is to be noted that although this exchange structures of a similar nature.

j plates 88 and |88 may beattached to one another and to the dehydrator tubes by means of ay tab structure, as are the fins shown in Figs. 8, 9,

f and l0. or they may be attached to one another by bolts or other suitable attaching means.

The arrangement-of the burner, control and' fuel tank of the refrigeration unit is shown in Figs. 16 and 17 where the fuel tank is indicated in general by the reference numeral |88, the. 'control designated by the reference numeral |84 and the burner by the reference numeral |88. The tank |88 is adapted to contain kerosene or some other suitable liquid fuel and is provided with a gauge |88 4and a filling spout |81. The tank is supported from the. lower wall |4 of the refrigeration space of Figures l to 3 by means of a bracket |08 which may be welded or bolted to the top of the tank slightly to the rear of the center of the top thereof. The bracket |08 may be bolted to a suitable bracket depending from the bottom wall `|4 .or it may be of a U-shape having one leg bolted to the vtank and the other to the bottom wall vof the refrigeration space. In either casefthe bracket |08 is bolted to the tank |03 and wall |4 in such a Way 'that it can be easily removed. The forward end of the tank |03 is supported by a bracket |09.which is bolted to a side frame member I of the cabinet in such a manner that it may be easily removed therefrom. The support of the fuel tank in this manner enables the fuel tank to be easily removed, which is a wide departure from prior art constructions.

Since the fuel tank may develop leaks, the advany tages of this typeA of support are quite pronounced.v The bottom of the fuel tank |03 com- The control |04- communicates by means of a conduit ||3 with the pilot reservoir I4 of the burner |05. ,The control |04 is carried by a saddle |5 bolted to and supported at its rear end by a bottom brace ||6 carried by the refrigerator cabinet and spanning the bottom of the cabinet from side to side thereof. The forward end of the saddle ||5 is bolted to a sill or 'front brace member I i1. The controlA |04I is fastened to the saddle by the bolts I8 and ||8 so that it may be easilyremoved therefrom. The burner unit |05 is also carried by the brace |5 and is fastened thereto for easy ,removal by the bolts. H9 and |20.

The burner unit is of an integral, weldedv or brazed 'construction and consists of -a drip pan |2| which is welded or brazed tothe pilot reserf voir ||4, as at |22 and |23.` Also welded to the pilot fuel tank is a supporting member |24 and a tube |25 which functions as a pilot wick` casing and as a feed tube for the channel |26 carrying the main wick. I'he channel |26 is formed from two annular members |21 and |28. Themembers |21 and |28k are bent to form supports for the burner tubes at |29 and |30. The pilot reser-fl voir ||4 is provided with a threaded inlet |3| and a cleanout tube |32. The tube |32 is so1- dered or brazed into the top of the pilot reservoir ||4 as indicated at |33, and is provided with a perforated cap |34. v

It is to be noted particularly that the upper or free end of the clean-out tube |32 is located at a point considerably above the normal fuel level inthe burner.' In prior art constructions, a clean-out plug was provided below the normal fuel level and this type of construction was subject to leakage. As is shownparticularly in Fig. 19, the clean-out duct is slanted forwardly. This facilitates the attachment of a suction line when. drainage of the pilot reservoir is necessary. Byl attaching an airline to the clean-out tube .|32 or the inlet |3'|., the pilot reservoir may be conveniently blown or cleaned.

system and including `a. still-absorber and evaporator connected in operative relation and an absorbercoil adapted to receive hot fluid from the still-absorber at the beginning of the absorption period, a condenser connected to said evaporator for passage of refrigerant to and from the evaporator and condenser, said condenser including an air-cooled coil positioned in air ow relation with said absorber coil so that air heated by said ab.-

sorber coil will flow through and transmit heat to the condenser coil whereby refrigerant within said condenser coil will be increased in pressure so as to expedite the discharge of refrigerant from said condenser at the beginning of the absorption period.

2. In an intermittent absorption refrigeration apparatus operating according` to the 1-3--2 system and including a still-absorber and an evaporator and an absorber ycoil adapted to receive hot fluid from the still-absorber at the beginning of the absorption period, a.v condenser connected to said evaporator for passage otre-,- frigerant to and from the evaporator and condenser; said condenser including a coil positioned adjacent and above said absorber coil and in heat `exchange relation therewith so as to receive heat from said absorber coil whereby refrigerant within said condenser coil will be increased in pressure so 'as to expedite the discharge of refrigeant from said condenser.

3. Inan intermittent absorption refrigeration apparatus operating according to the 1-,3-2

system and including a Vstill-absorber and an.

4. In an intermittent absorption refrigeration I lapparatus' operating vaccording to the 1--3--2 system and including a still-absorber and an evaporator connected Sin operative cycle, and an absorber coil :onnected to the still-absorber and adapted to receive hot fluid from the still ab- Itl is to be noted that the fuel burner herein disclosed is a completely self-contained unit. It

and burner of the unit. Referring to Fig. 16, it

is to be noted that the wall I'Ia, the -passage 22 and the flue 23, shown in dotted lines.v

Weclaimz Fig. l, are indicated in l. In en intermittent'v absorption refrigeration apparatus operating' according -to the 1-3-2 sorber at the beginning of the -absorption period, a vcondenser' -assembly comprising a condenser cooling coil, a condenser receiver and a sump,

said condenser cooling coll being connected to the sumpat its inlet end and to the receiver at its outletl end and said condenser receiver being connected to said sump adjacent the bottom thereof, said condenser cooling coil and said con-` denser receiver being positioned above and below the aforementioned absorber coil respectively, and said sump being connected at itslower por-f tion 4thereof with the evaporator so that during the generating period refrigerant to be condensed will be supplied to the sump, condensed in the condenser cooling coil and stored in the condenser receiver, and duringv the absorption period the' pressure in the condenser cooling coil 'will be.A increased so as to expedite the discharge of the collected refrigerant from the condenser receiver through the sump to the evaporator.

5. In a refrigerator of the intermittent absorp- A tion 4type including a still-absorber, an'evapo- 'rator and means to connect the same in opera- .tive cycle, mends to remove absorbent accumulating in the evaporator at the beginning of the generating cycle, said means terminating at one endin the evaporator and communicating at the other vend with the still-absorber, and means to I equalize the pressure in said second mentioned means shortly after lthe beginning of the gen.- erating cycle, said last mentioned means communicating with the second mentioned means at a point intermediate its ends.'

6. In a refrigerator of the intermittent absorption type including a still absorber, an evaporator and means to connect the same in operative cycle, means to remove absorbent accumulating in the evaporator, said means terminating at one end in the evaporator and communicating at the other ,end with the still-absorber, means.

to equalize the pressure in'said second-mentioned means shortly after the beginning of the generating cycle, and additional means to equalize the pressure in said first-mentioned means continuously throughout the generating cycle, both of said last-mentioned means communicating With the second-mentioned means at a point'intermediate its ends.

'7. In a refrigerator of the intermittent absorp type including a still-absorber, an evaporator and means to connect the same in operative cycle, means to remove absorbent accumulating in the evaporator at the beginning of the generating cycle comprising a conduit having an enlarged section intermediate its ends and connected to a low Ipoint. in the evaporator at one end and to a trap interposed in circuit between the still-absorber and the evaporator, at the other end, and means to equalize the pressure in said conduit shortly after the beginning of the generating cycle, said last mentioned means communicating with the conduit at its enlarged i section.

8. In a refrigerator of the intermittent absorption type including a still-absorbeigan evaptive cycle including a trap and a dehydrator" connected to the trap, means to remove absorb-v ent accumulating in the evaporator comprising a drain conduit connected to the evaporator by a plurality of conduits terminating at different levels therein and liquid-sealed at its other end in the connection leading from the dehydrator .orator and means to connect the samein opera-f to the trap, and means to prevent` drainage through said conduit during the generating cycle comprising a conduit communicating with the drain conduit at a point intermediate its ends, at one end, and with a chamber in heat exchange with hot gases flowing from the still-absorber, at its other end.

10. In a-refrigerator of the intermittent absorption'type including a still-absorber, an evaporator and means to connect the same in operative cycle including a trap, a dehydrator and a gas and liquid separating chamber connected to the dehydrator and tra ,means to remove absorbent accumulatingin t e evaporator comprising a drain conduit connected t6" the evaporator' i sorption type including a still-absorber, an evaporator and means to connect the same in operaf tive cycle, means to remove absorbent accumu-f lating in the evaporator, said means terminating at its upper end in the evaporator and communicating at its other end with the still-absorber, and means to equalize the pressure in said second mentioned means shortly after the beginning of the generating cycle, said last mentioned means having one end in heat exchange relation with the hot gases evolved from the stillabsorber during the generating cycleA and the other end communicating with the second mentioned means at a point intermediate its ends.

12. In a refrigerator of the intermittent absorption type including a still-absorber, an evaporator and means to connect the same in operative cycle including a trap, means to remove absorbent accumulating in the evaporator, said means terminating at one end in the evaporator and connected at the other end to the still-absorber and including an enlarged section inten mediate its ends, and means to equalize the pressure in said second mentioned means shortly after the beginning of the generating cycle, said last mentioned means communicating with the upper portion ofthe enlarged section and with the aforementioned trap and being effective to tive cycle including a trap, means to remove absorbent accumulating in the evaporator, said means terminating at one end in the evaporator and communicating at the other end with the still-absorber and including an enlarged section intermediate its ends andl means to equalize the pressure in said second mentioned means shortly after the beginning of tle generating cycle, said last mentioned means comprising an auxiliary chamber communicating with the trap below the normal liquid level therein and at a point adjacent its top with the aforementioned enlarged section so as to supply'volatilized refrigerant from the trap to the enlarged section.

14. In a refrigerator of the intermittent absorption type including a still-absorber, an evap- ,orator and means to connect the same in operative cycle including a trap, means to remove absorbent accumulating in the evaporator said means terminating at one end inthe evaporator -and connected at the other end to the still-ableast partially within the trap and communieating at a-point adjacent its top with the aforementioned enlarged section so as to supply volatilifiad refrigerant from the trap to the enlarged sec on.

15. In a refrigerator of the intermittent absorption type including a still-absorber, an evaporator and means to connect the same in operative cycle including a trap connected to the stillabsorber by a steam tube, means to remove absorbent accumulating in the evaporator, said means terminating at one end in the evaporator and communicating at the other end with the still-absorber, and means t'o equalize the pressure in said second means shortly after the beginning of the generating cycle, said last mentioned means' comprising an auxiliary chamber connected to the trap and surrounding the aforementioned steam tube in heat exchange relationship and communicating adjacent its upper portion with the first mentioned means at a point intermediate its ends so as to supply volatilized refrigerant to said second mentioned means to equalize the pressure therein.

16. In a refrigerating system of the intermittent absorption type including a still-absorber, an evaporator and means to connect the same in operative relation including a trap, a gas and liquid separating chamber connected to the trap at its lower end and to the evaporator at a point above the normal liquid level in the separating chamber, and a dehydrator including a plurality of connected conduits communicating with said trap at its inlet portion and with said gas and `liquid separating chamber at its outlet portion.

17. In a dehydrator for an absorption refrigeration system. a trap, an inlet for gas to be -dehydrated communicating with the lower portion of the trap, an outlet for the gas to be dehydrated communicating with the upper portion of the trap, a plurality of spaced conduits communicating with each -other and with said outlet, means connecting the conduits to the trap at their lower portions, an outlet for dehydrated gas communicating with the conduit remote from the trap and an outlet for liquid communicating with an intermediate portion of said trap.

18. In a refrigerator of the intermittent absorption type including a still-absorber andan evaporator, means to connect the same in operative relation, including a. dehydrator comprising a plurality of connected heat exchange conduits sloped from the horizontal, a trap interposed in circuit between the still-absorber and the evaporator, a gas and liquid separating chamber connected to said trap, means to connect the gas and liquid separating chamber with the lower portion of the dehydrator coil, and means above the normal liquid level therein to connect the gas and liquid separating chamber with the evaporator.

19. In a refrigerator of the intermittent absorption type including a still-absorber, an evaporator and means to connect the same in operative cycle, means to remove absorbent accumulating in the evaporator at the beginning of the generating cycle, said means terminating at one end in the evaporator and communicating at the other end with the still-absorber, means providing -a liquid seal for the still-absorber end of said last mentioned equalize the pressure in said absorbent removing means shortly after the beginning of the generating cycle, said last mentioned means commeans, and means to' municating with the absorbent removing means at a point intermediate its ends.

20. In a refrigerator of thelintermittent absorption type including a cabinet provided with a refrigeration space in the forward upper portion thereof, an evaporator in the refrigeration space, a still-absorber, an air cooled dehydrator, and an air cooled condenser operatively connected to said evaporator, a iiue in said cabinet extending substantiall;7 from top to bottom thereof, said ue being open at thetop and bottom for a circulation of air therethrough and having a widened portion positioned at least in part below said refrigerationspace, and a relatively long narrow portion positioned tothe rear of said space, said widened portion housing said condenser, said dehydrator having a relatively narrowv cross section and being'housed in the narrow portion of said iiue and substantially conforming in width to the width of said ue so that air passing through the condenser and warmed thereby will flow through the dehydratorand the flow of said air will be induced by the heat given oi by the dehydrator, and a second independent flue having an inlet and outlet housing said still-absorber.

L21. 1n e. refrigerator of the intermittent ab# sorption type including a cabinet provided with a refrigeration space in the forward upper portion thereof, an evaporator in the refrigeration space, a still-absorber, an air cooled dehydrator including a plurality of heat exchange conduits, and an air cooled condenser operatively connected to said evaporator, a flue in said cabinet extending substantially from top to bottom thereof, said iiue being open at the top and bottom for a circulation of air therethrough and having a widened portion positioned at least in part below said refrigeration space, and a. relatively long narrow portion positioned to the rear of said space, said widened -portion housing said condenser, said dehydrator having a relatively narrow cross section and being housed in the narrow portion of said flue and substantially conforming in width to the width of said ilue so that air passing through the condenser and warmed thereby will now through the dehydrator and the ow of said air will be induced by the heat given off by the dehydrator, and a second independent ue having an inlet and outlet housing said still-absorber.

v22. Intermittent absorption refrigeration apparatus comprising a cooling chamber, an evaporator disposed in said cooling chamber, a stillabsorber, a condenser, an absorber coil, and a deirydrator connected in operative relation to' said evaporator, said condenser including a re- -ceiver and a coil constructed and arranged to receive heat from said absorber coil, said condenser coil being connected to said evaporator through a liquid seal at one of its ends and having its other end connected to said condenser receiver whereby when refrigerant within said condenser coil is heated by said absorber coil, the pressure in said condenser coil and condenser receiver will beincreased to expedite the discharge of refrigerant from said condenser receiver.

JOHN LITHGOW.

LESLIE K. JACKSON.

CERTIFICATE oF CORRECTION; Patent Ng. 2,515,707. March 9, 19h5- JOHN LITHGOW, ET AL.

It is hereby Certified that error appears in the printed specification of the above numberedpa-tent requiring correctionas follows; Pagelp, first column, line', for "storabe" read --storage--g and second column, vline 55,

for "a cenduit read --conduit 55; line 66, for tray 50 read --trap 50"; page 8, first column, line 1, claim 5, for "mende" read --means-; line 25- 26, claim Y', for "absorp read --absorption--g and that the said Letters Petent al'rould be read with this correction therein that the same may oo nfom to the record of 'the case in the Patent Offiee.v S1gne1:and sealed this 11th day of'May; A, D. 191;,5.

Henry Van Arsldale, (Seal) Acting Commissioner of Patents., 

